Pump.



0. W. SIDWELL. PUMP.

APPLICATION FILED APR. 30, 1913.

Patented June 8, 1915.

W. SEDWELII, OF DELTA, PENNSYLVANIA.

PUMP.

To all whom it may concern: '1

Be it known that I, Gnarmns W. SmwELL, a citizen of the United States,residing at Delta, in the county of York and State of Pennsylvania, haveinvented certain new and useful Improvements in Pumps; and I. do herebydeclare the following to be a full,

' clear, and exact description of the invention, suclras will enableothers skilled in the art to which it appertains to make and use thesame.

This invention comprehends improvements in pumps and relates more.particularly to those of the type which employ a plurality ofintermeshing rotary pistons.

The primary object of the invention resides in the provision of a piunpof this type having peculiarly shaped pistons which may be rotated indifferent directions depending upon the ports into which it is desiredto draw and discharge a fluid.

Although the term ffiuid will be used throughout the specification, itwill be understood that the pump will work equally as well when used forpumping air or gas as when. used for pumping water or some other liquid,and may also be used as a vacuum pump.

The invention also" aims to provide a rotary piston for pumps whichshall be of extremely simple construction, strong, dur'ahle, and of suchconstruction as to provide a very efficient pump.

With these and other objects in'view, as will become more apparent asthe description procecds, the invention consists in certain novelfeatures of construction, combi- 4 nation, and arrangement of parts, aswill be hereinafter described and claimed.

.For a complete understanding of my invention, reference is to be had tothe following description and drawings, in which,

Figure 1 is a bottom view of my improved pump, the casing being partlybroken away and partly in section, and the piston being shown inelevation, Fig. 2 is a vertical sectional view taken on the plane ofline .2-2 of Fig. 1, and, Fig. 3 is a detail view in elevation, of oneof the pistons.

Referring in detail to the drawings by numera1s,.5 designates the casingclosed at its ends by the walls 6 and 7 and provided upon its lower sideadjacent its ends with the ports 8 and 9 and upon its upper sidecentrally of its ends with a port 10. Dis- Specification of LettersPatent. Application tiled Apr-i180, 1913. Serial No. 764,616.

other will be rotated thereby.

accompanying A i Patented line 8, 1915.

posed within the casing and extending longitudinally thereof, are therotary pistons,

generally designated 11 and 12, having the stub shafts-or trunnions 13extending longltudinally from their ends through the walls 6 and 7,which form bearings.

The pistons are identical in construction and are formed, as clearlyshown in Fig. 3, where it will be seen that one half of the piston isformed with the right hand spiral grooves 14 which run half way aroundthe piston and which extend from the center to one end thereof. Theother end of the piston is formed with the left hand spiral grooves 15,which connect at their inner ends with the grooves 14. The grooves 14and 15 form acute angles with the longitudinal axis of the piston andappear arouately shaped in cross-section. The grooves 14 upon one halfof the piston form the.

right hand spiral ribs 16 and the. grooves 15 upon the other half of thepiston form the left hand spiral ribs 17. The tops of the ribs areessentially semicircular. as

' shown in Fig. 2.- The piston might be considered as being formed of abar having concave sides and rounded edges. one half of the bar beingtwisted in one direction and the other half being twisted in the otherdirection. Each half is turned'through an are of 180 so that the ribsand grooves will extend half way around the piston.

When the pistons are assembled within the casing 5, the right handgrooves and ribs of one piston are opposed to the left hand grooves andribs upon the other pistonv and when thus arranged, the pistons meshwith one another so when one is driven the This fact obviates thenecessity of driving positively more than one of the pistons. Necessarypower may be applied to one of the trunmons 13.

walls 6 and 7 closely engage the ends of the pistons so as to preventleakage from the grooves at the outer ends thereof.

From the foregoing description taken in connection with the accompanyingdrawings, it will be seen that I have provided a pump havingintermeshing rotary pistons of extremely simple construction, which willoperate so as to draw a fluid into the casing and discharge the sametherefrom. The construction which I have shown may be used as a pump,fan or as a motor. If a fluid is forced into the port 10 under pressureand allowed to discharge through the ports 8 and 9, the pistons will bedriven and act as rotors. The same action, in a reverse direction, willtake place when the fluid is forced into the ports 8 and 9 and allowedto discharge through the port 10.

It is to be understood that while I have shown and described thepreferred embodiment of my invention, I do not wish to be limited tothis exact construction, combination, and arrangement of parts, but maymake such changes as will fall within the spirit and scope of theinvention.

Having thus described my invention, What I claim is A pump including apair of intermeshing pistons, each of which comprises a relatively thinbody, said bodybeing extended in the line of a compound curve forone-half of its length in one direction, and for the remainder of itslength in the opposite direction to form a pair of opposite spiral ribs,and curved edges formed on the ribs to facilitate the intermeshing ofthe pistons, the line of curve at the terminal of each rib beingparallel with the axis of the body and in the same diametrical plane.

In testimony whereof I aflix my signature in presence of two witnesses.

CHARLES W. SIDWELL.

Witnesses:

W. W. SELLERS, H. N. LLOYD.

